// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_MOJO_CLIENTS_MOJO_DECRYPTOR_H_
#define MEDIA_MOJO_CLIENTS_MOJO_DECRYPTOR_H_

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread_checker.h"
#include "media/base/decryptor.h"
#include "media/mojo/interfaces/decryptor.mojom.h"
#include "mojo/public/cpp/bindings/binding.h"

namespace media {

class MojoDecoderBufferReader;
class MojoDecoderBufferWriter;

// A Decryptor implementation based on mojom::DecryptorPtr.
// This class is single threaded. The |remote_decryptor| is connected before
// being passed to MojoDecryptor, but it is bound to the thread MojoDecryptor
// lives on the first time it is used in this class.
class MojoDecryptor : public Decryptor {
public:
    explicit MojoDecryptor(mojom::DecryptorPtr remote_decryptor);
    ~MojoDecryptor() final;

    // Decryptor implementation.
    void RegisterNewKeyCB(StreamType stream_type,
        const NewKeyCB& key_added_cb) final;
    void Decrypt(StreamType stream_type,
        const scoped_refptr<DecoderBuffer>& encrypted,
        const DecryptCB& decrypt_cb) final;
    void CancelDecrypt(StreamType stream_type) final;
    void InitializeAudioDecoder(const AudioDecoderConfig& config,
        const DecoderInitCB& init_cb) final;
    void InitializeVideoDecoder(const VideoDecoderConfig& config,
        const DecoderInitCB& init_cb) final;
    void DecryptAndDecodeAudio(const scoped_refptr<DecoderBuffer>& encrypted,
        const AudioDecodeCB& audio_decode_cb) final;
    void DecryptAndDecodeVideo(const scoped_refptr<DecoderBuffer>& encrypted,
        const VideoDecodeCB& video_decode_cb) final;
    void ResetDecoder(StreamType stream_type) final;
    void DeinitializeDecoder(StreamType stream_type) final;

    // Called when keys have changed and an additional key is available.
    void OnKeyAdded();

private:
    // Called when a buffer is decrypted.
    void OnBufferDecrypted(const DecryptCB& decrypt_cb,
        Status status,
        mojom::DecoderBufferPtr buffer);
    void OnBufferRead(const DecryptCB& decrypt_cb,
        Status status,
        scoped_refptr<DecoderBuffer> buffer);
    void OnAudioDecoded(const AudioDecodeCB& audio_decode_cb,
        Status status,
        std::vector<mojom::AudioBufferPtr> audio_buffers);
    void OnVideoDecoded(const VideoDecodeCB& video_decode_cb,
        Status status,
        mojom::VideoFramePtr video_frame);

    // Called when done with a VideoFrame in order to reuse the shared memory.
    void ReleaseSharedBuffer(mojo::ScopedSharedBufferHandle buffer,
        size_t buffer_size);

    base::ThreadChecker thread_checker_;

    mojom::DecryptorPtr remote_decryptor_;

    // Helper class to send DecoderBuffer to the |remote_decryptor_| for decrypt
    // or decrypt-and-decode.
    std::unique_ptr<MojoDecoderBufferWriter> mojo_decoder_buffer_writer_;

    // Helper class to receive decrypted DecoderBuffer from the
    // |remote_decryptor_|.
    std::unique_ptr<MojoDecoderBufferReader> mojo_decoder_buffer_reader_;

    NewKeyCB new_audio_key_cb_;
    NewKeyCB new_video_key_cb_;

    base::WeakPtrFactory<MojoDecryptor> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(MojoDecryptor);
};

} // namespace media

#endif // MEDIA_MOJO_CLIENTS_MOJO_DECRYPTOR_H_
